Taxpayer lives in Canada.  Never steps foot in USA.   He will never apply for Social Security benefits. He is a silent, investor partner in a business in USA and received a K-1 with self-employment earnings.  How do I exclude those earnings for SE tax on his 1040-NR?

Internal Revenue Code §1402(b)

The term “self-employment income” means the net earnings from self-employment derived by an individual (other than a nonresident alien individual, except as provided by an agreement under section 233 of the Social Security Act) during any taxable year